2) Groovy TV Flashback: Twin Peaks
On April 8, 1990, the ABC series aired its first episode, and below you can watch three of its stars promote the show - Dana Ashbrook (Bobby Briggs) on Live with Regis and Kathie Lee on May 8, 1990; Kimmy Robertson (Lucy Moran) on Late Night with David Letterman on October 25, 1990; and Mädchen Amick (Shelly Johnson) on Into the Night With Rick Dees on January 3, 1991.

3) Groovy TV Preview: The Leftovers
The third and final season of this HBO drama premieres on April 16.

4) Groovy Gal: Christine Baranski
The actress is a guest on The Late Late Show with James Corden and his other guests, Claire Danes and Jack McBrayer.

5) Groovy Gal: Sigourney Weaver
The actress promotes her new film, The Assignment, on The Late Show with Stephen Colbert.

6) Groovy Guy: Louis C.K.
The comedian, whose new Netflix special, 2017, premieres on April 4, is a guest on The Late Show with Stephen Colbert.

7) Groovy Guy: Andrew Rannells
The actor promotes the series finale of HBO's Girls (which airs on April 16) on Late Night with Seth Meyers.

8) Groovy Guy: Billy Eichner
The actor stars in a parody of his TV series, Billy on the Street, on Sesame Street.

9) Groovy Guy: Randy Rainbow
He interviews Ivanka Trump.

10) Groovy Guy: Nick Adams
The actor performs with The Skivvies (Lauren Molina and Nick Cearley) at The Green Room 42 at the YOTEL New York.